The present invention relates to a device for controlling a plurality of electrical consumers according to the preamble of the main claim. Electrical consumers may have LEDs in the form of strands in particular. On the other hand, the invention includes and claims the act of providing these electrical consumers in the form of electrical consumers which do not have semiconductor-based lamps, in particular no LEDs, and instead are implemented as batteries (in which case the present invention is then embodied to control a plurality of such batteries as a charging device) and additionally or alternatively, the electrical consumers have electric motors, or again alternatively, they may have a plurality of galvanic devices to which a constant electrical current is supplied.
With regard to the state of the art, reference should first be made to the LED technology.
In particular for the purpose of manufacturing intensely bright lights, (high-performance) LEDs in strand form are combined as a series connection, to then be able to deliver the cumulative light intensity (on a suitable carrier). FIG. 2 illustrates such an arrangement, in which a first control node CH1 and a second control node CH2 each represent the switching point for a series connection of a plurality of LEDs (10 per strand here).
The need for achieving a uniform light output of each LED leads to the fact that they are arranged as a series connection in the manner described here; a typical voltage drop of approximately 3.2V with a white LED then results in voltages of approximately 32V being applied per strand in the arrangement illustrated in FIG. 2. From the goal of not exceeding safety limits for low voltages, this leads to the result that multiple strands are carried in parallel, for example, with two strands in the manner illustrated in FIG. 2, when orders of magnitude of 15 to 20 LEDs are exceeded.
However, component tolerances and other manufacturing-related deviations result in the fact that, in the absence of separate measures, parallel circuits of multiple strands will develop voltage differences, the result being an uneven current distribution among the individual strands. This leads to an irregular brightness of the respective LEDs in an advantageous manner and leads to disadvantages in terms of the lifetime of the lamps.
Accordingly, to achieve a uniform luminous efficiency of parallel-connected strands, each having a plurality of LED lamps, it is customary in the state of the art to connect a current regulator upstream from each strand to adjust and/or regulate the current (I1 in strand 1, I2 in strand 2 in FIG. 2) flowing in the strand at the same level.
However, this is complicated because a separate current regulating unit is required for each strand, so that there is a demand for a simplified current regulation for a plurality of parallel strands of LED lamps provided in the form of a series connection, in particular in the field of large-scale manufacturing technology and/or consumer applications. Furthermore, this basic demand exists not only for the LED lamps, which are used only for the context of this problem but instead there is also such a demand for any consumers, typically those such as batteries (to be charged) which receive a constant (regulated) current, electric motors (in particular stepping motors) or galvanic systems. All these consumers as well as additional electrical consumers which are typically operated at a constant current are considered to be “electrical consumers” in the remaining text in the sense of this invention, wherein a preferred implementation form of the invention excludes semiconductor-based lamps, in particular LEDs, from the invention.
The object of the present invention is therefore to simplify a generic device for controlling a plurality of electrical consumers, in particular to reduce the structural complexity and/or hardware complexity, while at the same time providing a circuit which makes it possible to apply a current to the plurality of electrical consumers and to do so in an energy-efficient manner with a minimal power loss.